Effects of drospirenone/estradiol on steroid receptors and Bcl-2 in the postmenopausal endometrium.

OBJECTIVE: To evaluate the effect of drospirenone with 17β-estradiol on the histology and expression of estrogen and progesterone receptors and of Bcl-2 protein, in endometrium of postmenopausal women.

METHOD: Forty postmenopausal women, including controls, participated in this study evaluating oral hormone replacement treatment combining 2 mg/day of drospirenone with 1 mg/day of 17β-estradiol administered for a 24-week period. The effect on the endometrium was assessed by histology and the apoptosis marker Bcl-2. The immunoexpression of estrogen (ER) and progesterone (PR) receptors in the endometrium was also measured.

RESULTS: No increase in endometrial thickness was evident after either treatment, although endometrial histology was atrophic in most biopsies. The drospirenone/estradiol group showed higher expression of ER and PR in glandular epithelium compared to stroma, but the Bcl-2 protein was more immunoreactive in stroma than in glandular epithelium. Compared to controls, drospirenone/estradiol users showed higher immunoexpression of ER, PR and Bcl-2 in both glandular epithelium and endometrial stroma.

CONCLUSION: A 24-week course of drospirenone with 17β-estradiol resulted in low proliferation and was shown to lead to atrophic endometrium. The novel progestogen drospirenone seems to have favorable effects on the endometrium of postmenopausal women due to its pro-apoptotic action in glandular epithelium.